A typical aircraft mounted gas turbine engine incorporates thrust reversal devices to slow the plane during landing. Among the devices used are multiple vane structures which direct compressor air in a direction opposite to the direction of aircraft travel to produce a braking effect. Reverse thrust is achieved when a transcowl translates aft to deploy blocker doors in the fan bypass air stream, at the same time opening passages which redirect fan air to exit through the multiple vane structures commonly know as "cascades".
These cascades usually comprise a plurality of individual magnesium die castings or aluminum vanes joined to a pair of platforms by dip brazing, which produces a relatively heavy structure of multi part construction. In addition, due to the assembly method, the critical joint areas between the vane and platform are susceptible to fatigue or stress failure.
Attempts have been made to produce cascades from composites. However, due to the complex geometry of the turning vane surfaces, efforts to produce the cascades as composites from woven fiber in a hand lay-up process have been generally unsatisfactory, suffering from poor dimensional reproducibility between parts and high labor costs. Such parts in the past, whether of metal or woven fabric composite, have exhibited relatively low load carrying capability, with the woven composite exhibiting fiber discontinuity in seam areas and variability of fiber orientation.